The Montreal Protocol is an international treaty designed to protect the ozone layer by phasing out the production of a number of substances believed to be responsible for ozone depletion. The phase out is planned via a timetable. For example, the substance hydro chlorofluorocarbon has a first deadline of 2015 and a final phase-out by 2030.

In its daily work, UNIDO focuses on cost-effective ways to reduce ozone-depleting substances such as freons, halons and chlorofluorocarbons, in the areas of refrigeration, plastic foams, halons, solvents, fumigants and aerosol.

Once the government of a developing country identifies a company that requires assistance in eliminating an ozone depleting substance that originates during the production cycle, it approaches UNIDO with a request to find a solution and introduce a more advance technological process in line with international standards.